Bottom Line:
The top 27 drug candidates from the 165 hits were confirmed to have higher anti-persister activity than the current frontline antibiotics.Among the top 27 confirmed drug candidates from the 165 hits, daptomycin, clofazimine, carbomycin, sulfa drugs (e.g., sulfamethoxazole), and certain cephalosporins (e.g. cefoperazone) had the highest anti-persister activity.Our findings may have implications for the development of a more effective treatment for Lyme disease and for the relief of long-term symptoms that afflict some Lyme disease patients.

Affiliation: Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, MD 21205, USA.

ABSTRACTAlthough antibiotic treatment for Lyme disease is effective in the majority of cases, especially during the early phase of the disease, a minority of patients suffer from post-treatment Lyme disease syndrome (PTLDS). It is unclear what mechanisms drive this problem, and although slow or ineffective killing of Borrelia burgdorferi has been suggested as an explanation, there is a lack of evidence that viable organisms are present in PTLDS. Although not a clinical surrogate, insight may be gained by examining stationary-phase in vitro Borrelia burgdorferi persisters that survive treatment with the antibiotics doxycycline and amoxicillin. To identify drug candidates that can eliminate B. burgdorferi persisters more effectively, we screened an Food and Drug Administration (FDA)-approved drug library consisting of 1524 compounds against stationary-phase B. burgdorferi by using a newly developed high throughput SYBR Green I/propidium iodide (PI) assay. We identified 165 agents approved for use in other disease conditions that had more activity than doxycycline and amoxicillin against B. burgdorferi persisters. The top 27 drug candidates from the 165 hits were confirmed to have higher anti-persister activity than the current frontline antibiotics. Among the top 27 confirmed drug candidates from the 165 hits, daptomycin, clofazimine, carbomycin, sulfa drugs (e.g., sulfamethoxazole), and certain cephalosporins (e.g. cefoperazone) had the highest anti-persister activity. In addition, some drug candidates, such as daptomycin and clofazimine (which had the highest activity against non-growing persisters), had relatively poor activity or a high minimal inhibitory concentration (MIC) against growing B. burgdorferi. Our findings may have implications for the development of a more effective treatment for Lyme disease and for the relief of long-term symptoms that afflict some Lyme disease patients.

fig2: Susceptibility of log phase (3 days) and stationary-phase (7 days) B. burgdorferi to 50 µM drugs after a 5-day treatment. The percentages of residual live cells were determined using the SYBR Green I/PI assay.

Mentions:
In our preliminary studies, we determined that stationary-phase B. burgdorferi were refractory to killing by the frontline drugs, doxycycline or amoxicillin (Figure 2) and could thus serve as a persister model for drug screens. To qualitatively determine the effect of FDA-approved drugs on B. burgdorferi persisters, each compound (10 µL) from the pre-diluted stock was added to 7-day-old B. burgdorferi stationary-phase culture in the screening plate. The final volume per well was adjusted to 100 µL to achieve a final drug library concentration of 50 µM in the drug screen. The plates were sealed and placed in a 33°C incubator for 7 days.

fig2: Susceptibility of log phase (3 days) and stationary-phase (7 days) B. burgdorferi to 50 µM drugs after a 5-day treatment. The percentages of residual live cells were determined using the SYBR Green I/PI assay.

Mentions:
In our preliminary studies, we determined that stationary-phase B. burgdorferi were refractory to killing by the frontline drugs, doxycycline or amoxicillin (Figure 2) and could thus serve as a persister model for drug screens. To qualitatively determine the effect of FDA-approved drugs on B. burgdorferi persisters, each compound (10 µL) from the pre-diluted stock was added to 7-day-old B. burgdorferi stationary-phase culture in the screening plate. The final volume per well was adjusted to 100 µL to achieve a final drug library concentration of 50 µM in the drug screen. The plates were sealed and placed in a 33°C incubator for 7 days.

Bottom Line:
The top 27 drug candidates from the 165 hits were confirmed to have higher anti-persister activity than the current frontline antibiotics.Among the top 27 confirmed drug candidates from the 165 hits, daptomycin, clofazimine, carbomycin, sulfa drugs (e.g., sulfamethoxazole), and certain cephalosporins (e.g. cefoperazone) had the highest anti-persister activity.Our findings may have implications for the development of a more effective treatment for Lyme disease and for the relief of long-term symptoms that afflict some Lyme disease patients.

Affiliation:
Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, MD 21205, USA.

ABSTRACTAlthough antibiotic treatment for Lyme disease is effective in the majority of cases, especially during the early phase of the disease, a minority of patients suffer from post-treatment Lyme disease syndrome (PTLDS). It is unclear what mechanisms drive this problem, and although slow or ineffective killing of Borrelia burgdorferi has been suggested as an explanation, there is a lack of evidence that viable organisms are present in PTLDS. Although not a clinical surrogate, insight may be gained by examining stationary-phase in vitro Borrelia burgdorferi persisters that survive treatment with the antibiotics doxycycline and amoxicillin. To identify drug candidates that can eliminate B. burgdorferi persisters more effectively, we screened an Food and Drug Administration (FDA)-approved drug library consisting of 1524 compounds against stationary-phase B. burgdorferi by using a newly developed high throughput SYBR Green I/propidium iodide (PI) assay. We identified 165 agents approved for use in other disease conditions that had more activity than doxycycline and amoxicillin against B. burgdorferi persisters. The top 27 drug candidates from the 165 hits were confirmed to have higher anti-persister activity than the current frontline antibiotics. Among the top 27 confirmed drug candidates from the 165 hits, daptomycin, clofazimine, carbomycin, sulfa drugs (e.g., sulfamethoxazole), and certain cephalosporins (e.g. cefoperazone) had the highest anti-persister activity. In addition, some drug candidates, such as daptomycin and clofazimine (which had the highest activity against non-growing persisters), had relatively poor activity or a high minimal inhibitory concentration (MIC) against growing B. burgdorferi. Our findings may have implications for the development of a more effective treatment for Lyme disease and for the relief of long-term symptoms that afflict some Lyme disease patients.